<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>06_相对定位</title>
    <style>
        .fu {
            background-color: #ff0;
        }
        .fu>div {
            width: 100px;
            height: 100px;
        }
        .z1 {
            background-color: #f00;
        }
        .z2 {
            background-color: #0f0;
            /* 相对定位：不会脱离文档流，释放布局空间
               易懂参照物：自己原来的位置
               z-index:调整元素层级，整数，无单位，默认值0，数字越大层级越靠上*/
            position: relative;
            top: 50px;
            right: 50px;
        }
        .z3 {
            background-color: #00f;
            position: relative;
            z-index: 1;
        }
    </style>
</head>
<body>

<div class="fu">
    <div class="z1"></div>
    <div class="z2"></div>
    <div class="z3"></div>
</div>


</body>
</html>